STRIKE FIORDS 



153 



in close association exhibit a systematic northwest trend; 

 these are Icy Strait, Freshwater Bay, the main part of 

 Tenakee Inlet, and Peril Strait with its prolongation in 

 Hoonah Sound. The divergence of the branching fiords 

 at the head of Lynn Canal is also perplexing; for, while 

 each of these is so straight as to suggest an origin con- 

 nected with strike, they are not parallel, but diverge fan- 

 wise from a common point. 



The walls of Lynn Canal are well-defined features. At 

 the water's edge and for some distance above, their con- 

 tours are simple. There are few bays and no jutting prom- 

 ontories. The slope of the walls is not so steep as in 

 some fiords; it rarely exceeds 45, and in places is as low 

 as 30. Near the head of the canal the walls are well 

 defined up to an altitude of about 2,000 feet, the height 

 increasing toward the north and decreasing toward the 

 south. Higher up, the mountains exhibit a varied topog- 

 raphy: There 

 are U-shaped 

 troughs end- 

 ing as hang- 

 ing valleys at 

 many differ- 

 ent heights; 

 there are V-- 

 shaped gorges 

 modified at 

 bottom by 

 glaciers and 



FIG. 76. HANGING GLACIER, TAIYA INLET. 



The sill of the hanging valley is 3,500 feet above sea-level. For 

 Separated by more than 1,000 feet below the glacier the fiord wall is kept bare by 



narrow tent- 



form spurs. These troughs, gorges and spurs approach 

 the canal wall at all angles and there end. Some- 

 times they end abruptly, sometimes with a certain amount 

 of prolongation down the steep wall; but this prolon- 



